A fluorinated water and oil repellent is excellent in water and oil repellency and is used for water and oil repellent process of fibers. However, the fluorinated water and oil repellent is expensive, and accordingly a water and oil repellent composition comprising a fluorinated water and oil repellent and an extender in combination may be used as a water and oil repellent composition having its cost reduced while maintaining water and oil repellent performance. Further, an extender may be used to develop such characteristics that the color fastness of a dyed cloth will not deteriorate and the texture slippage of a cloth will not occur.
The water and oil repellent composition comprising such an extender in combination may be a composition comprising a paraffin wax, a fatty acid derivative, a silicone compound, a carboxyl group-containing polyethylene, etc. and a fluorinated water and oil repellent (for example, JP-A-1-156581), but it has problems such as insufficient water and oil repellent performance.
Namely, a large quantity of a surfactant is required to emulsify a water and oil repellent composition, thus decreasing the water and oil repellent performance of the resulting composition. Further, the particle size of the emulsified particles of the extender is large, whereby the storage stability of the composition tends to decrease. Further, there are such problems that the stability of a processing bath decreases, and the feeling of a processed fiber product significantly changes.
Further, when an extender is used, an ending phenomenon is increased in general. The ending phenomenon is such a phenomenon that in water and oil repellent process over a long period, the concentration of the water and oil repellent in a processing liquid decreases with time, and the water and oil repellent performance of a treated object will decrease.